Mozilla has explicitly said the DRM plugin won't run without user consent. How t...

higherpurpose · on May 14, 2014

Pretty sure it means it will run by default, and you'd have a to be part of a minority group on HN to know that you can even do that in Firefox.

bzbarsky · on May 15, 2014

https://hacks.mozilla.org/2014/05/reconciling-mozillas-missi... is pretty clear:

  As plugins today, the CDM itself will be distributed by
  Adobe and will not be included in Firefox. The browser
  will download the CDM from Adobe and activate it based on
  user consent.

The point being that you will be asked whether to download this thing, and if you say no it won't be downloaded.